Paper cup with outside caulking on bottom



1966 J. B. BOLCATO PAPER CUP WITH OUTSIDE CAULKING ON BOTTOM OriginalFiled Sept. 13, 1961 INVENTOR JOHN B. BoLcATo 1;; ATTORNEYS UnitedStates Patent 3,268,143 PAPER (3UP WITH OUTSIDE CAULKING 0N BOTTOM JohnB. Bolcato, Three Rivers, Mich, assignor to Continental Can Company, IncNew York, N.Y., a corporation of New York Original application Sept. 13,1961, Ser. No. 137,782, new Patent No. 3,202,065, dated Aug. 24, 1965.Divided and this application Nov. 13, 1964, Ser. No. 410,867

1 Claim. (Cl. 229--1.5)

This application constitutes a division of my copending commonlyassigned application for U.S. Letters Patent, Serial No. 137,782, filedSeptember 13, 1961, and now Patent No. 3,202,065.

This invention relates in general to new and useful improvements inpaper cups, and more particularly relates to the outside caulking of apaper cup to prevent leakage in the bottom seam thereof.

In the manufacture of paper cups, cups that leak through the bottomseams are unacceptable to the trade. Consequently, many cups may bescrapped even though they appear satisfactory. It is diflicult toprovide cups that definitely will not leak at the bottom seam because ofthe character of the adhesive employed in the formation of the seamduring the conventional manufacture of paper cups. The adhesive soapplied to paper cups is re lied upon to leakproof the seams, as well asbond them, but, frequently the adhesive shrinks during the setting orcuring stage causing the adhesive to break away from the surfaces of thepaper bottom and cup body and thereby permit liquid contained in the cupto leak through the bottom seam.

Accordingly, it is a primary object of this invention to provide a novelseal for the bottom seams of paper cups so that the liquid contained ina cup cannot leak through the bottom seams thereof.

A further object of this invention is to provide a novel paper cuphaving a seam between a bottom wall and a cup body, and the bottom seambeing leak-proof due to the presence of caulking compound in a positionat which maximum sealing is attained and where the caulking compound isnot readily discernible, thus effecting both an efficient and estheticcup construction.

A further object of this invention is to provide a novel paper cup ofthe type including a bottom construction and a cup body, the bottomconstruction including a bottom wall having a depending peripheralflange, the cup body having a reversely turned bottom edge disposedinwardly of the bottom flange and holding the bottom flange against theinterior of the cup body, means for adhesively bonding the bottom flangeto the cup body, and the cup body bottom edge, and caulking compoundsealing the cup body to the cup bottom with the caulking compound beingdisposed in a corner defined by the cup bottom and the cup body bottomedge.

With the above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following detailed description, the appended claim and the singleview illustrated in the accompanying drawing, in which the figure is avertical sectional view of a paper cup constructed in accordance withthis invention, and shows the novel bottom construction thereof withcaulking compound applied thereto.

Referring to the drawing in detail, it will be seen that there isillustrated in the figure a paper cup generally referred to by thenumeral 10. The cup includes the usual cup body 11 terminating at anupper end portion 12 in a curl 13. A lower end portion 14 of the cupbody 11 terminates in a cup bottom 15 being provided with a dependingperipheral flange 16.

Patented August 23, 1966 ice The cup bottom 15 is telescoped within thelower end portion 14 of the cup body 11 with the peripheral flange 16 inabutting engagement with an inner surface 17 of the cup body 11. Aterminal lower edge 18 of the cup body 11 is reversely turned and isdisposed inwardly of the peripheral flange 16 of the cup bottom 15. Theflange 16 is secured to both the inturned terminal edge 18 and to theinner surface 17 of the cup body 11 by means of a suitable adhesive 20in a customary manner.

The construction of the cup 10 illustrated in the figure is accomplishedin the conventional manner with one difference. The adhesive 20 may bevaried, as is deemed advisable, to provide for a more secure mechanicaljoint between the cup bottom 15 and the cup body 11 without emphasisupon the forming of a complete seal in the seam between the cup bottom15 and the cup body 11. However, after the cup 10 has been formed in thecustomary manner and normally, but not necessarily, before it isinitially packed, caulking compound 21 is applied to the cup bottom 15to assure the sealing of the seam between the cup bottom 15 and the cupbody 11. The caulking compound 21, as is clearly shown in the figure, isdeposited in the corner of the bottom at the intersection of theinturned terminal edge 18 and the cup bottom 15 to assure against anyleakage at this point. Thus, any liquid dispose-d within the cup 10 thatshould seep pass the seam between the cup bottom 15 and the cup body 11,will be stopped and effectively sealed by means of the caulking compound21. Also, the caulking compound 21 will seal the extreme end of the lapseam 22 of the cup body 11, as is clearly illustrated in the drawing.

It is to be understood that it is not necessary for the caulkingcompound 21 to dry or set rapidly upon the application thereof to thecup because its primary purpose is not adhesion. Consequently, thecaulking compound 21 may be formulated to remain pliable or plastic fora long period so that there will be little or no tendency for thecaulking compound to contract to permit the passage of liquid.Therefore, while the adhesive 20 used in forming the bottom seam of thepaper cup 10 may shrink upon setting or driving and thus tend to produceleaks, the caulking compound 21 will remain pliable and seal the papercup where it would otherwise leak due to the shrinking of the adhesive.

It is preferred that the caulking compound 21 consists of a suitablebinder filled with an inert material. Examples of such caulking compoundare water based emulsions such as those used in the formation ofadhesives presently used in the bottom seams and may include water basedemulsions of modified polymers, which may be acrylics, acetates, vinyls,etc. These water based emulsions are filled with inert materials, suchas clays, chaulks, silicates, rubber, etc.

The cup 10 is preferably fabricated in the manner disclosed in PatentNo. 3,202,065, i.e., by directing the caulking compound 21 onto the cupbottom 15 while the cup 10 is inverted and is rotating. As a result, thecaulking compound 21 is directed by means of centrifugal force into theinterstices of the seam between the bottom wall 15 and the cup body 10in the manner generally shown in the figure to assure a satisfactorysealing of the bottom seam. The centrifugal force is particularlyeffective in directing the caulking compound 21 into an annular areabetween a free edge 23 of the terminal edge 18 and a radius portion 24joining the cup body 15 to the peripheral flange 16. The caulkingcompound 21 is thus disposed in a generally L-shaped configuration intransverse section having leg portions 25, 26 and a portion 27 betweenthe free edge 23 and the radius portion 24. The portion 27 of thecaulking compound 21 is thicker than either of the leg portions 25, 26and is respectively parallel and normal to these leg portions.

From the foregoing, it will be seen that novel and advantageousprovision has been made for carrying out the desired end. However,attention is again directed to the fact that variations may be made inthe example cup disclosed herein without departing from the spirit andscope of the invention, as defined in the appended claim.

I claim:

A cup comprising a tubular body, a bottom received in said body ininternal telescopic relationship at an end portion thereof, said bottomincluding a bottom wall generally normal to the cup body axis and adepending peripheral flange joined by an integral radius portion to saidbottom Wall, said body edge portion having a reversely turned terminalportion disposed inwardly of said bottom flange, said terminal portionterminating in a free edge, said free edge terminating adjacent andspaced from said bottom Wall radius portion, means adhesively bondingsaid bottom flange to both said cup body end portion and said terminalportion, and an annular band of caulking compound sealing said cup bodyto said cup bottom, said band of caulking compound being disposed in acorner of said cup defined by said terminal portion and said bottomwall, said caulking compound band being generally L-shaped in transversecross section and having first and second caulking compound leg portionsoverlying portions of the respective bottom wall and terminal flangeportion, and a portion of said caulking compound band in a plane commonto said first leg portion being disposed in said space whereby saidcorner is wholly sealed by said band of caulking compound.

References Cited by the Examiner UNITED STATES PATENTS 1,147,421 7/1915Morewood 2295.6 1,234,683 7/ 1917 Myerscough 2295.6 1,997,188 4/1935Gazette 2295.6 2,085,847 6/1937 Carew 229-56 2,141,556 12/1938Reifsnyder 2293.1 X 2,193,521 3/1940 Roach 2291.5 2,735,604 2/1956Zerlin 229-3.1 X 2,834,533 5/1958 Carew 229-52 2,917,215 12/1958 Psatyet al. 2291.5 3,164,314 1/1965 Waycie 229-1.5

GEORGE O. RALSTON, Primary Examiner.

